Industrial process controllers have many different configurations and are used in many different applications. Controllers may be mounted in a control room or may be part of a distributed control system. Controllers are often designed to maintain process variables at desired reference points known as setpoints. A system designed to control a process variable may be called a control loop.
Control loops can experience problems that result in poor control of process variables. A problem can occur with a final control element, a sensor, tuning parameters of a controller, or something else. If the control loop is isolated or is only one of a handful of control loops, an experienced control engineer can usually determine what the problem is within a reasonable period of time. In a large industrial facility, however, it is not uncommon to have hundreds or thousands of control loops with their associated controllers. In such an industrial facility, it is often difficult to determine which control loops are experiencing problems, especially when a problem in one control loop adversely affects other control loops.
In a typical scenario, the performance of each control loop can be rated against multiple Key Performance Indicators (KPIs). However, there are often numerous indicators to be monitored for all control loops in an industrial facility.